Online Port Scanner
Analyze server availability and security by scanning for open ports and active services.
Maximum scan range: 50 ports per request for stability.
Understanding Server Ports & Security
In networking, a Port is a communication endpoint. When a service like a web server or an email server runs on a machine, it "listens" on a specific port for incoming connections. Our Online Port Scanner helps you identify which of these endpoints are accessible from the public internet.
Why Scan for Open Ports?
Scanning ports is a critical step in server hardening. Unnecessary open ports can be gateways for malicious actors. By auditing your server, you can ensure that only required services (like HTTP/HTTPS) are exposed, while sensitive services (like MySQL or SSH) are properly firewalled.
TCP vs. UDP Scanning
Most web services use TCP (Transmission Control Protocol), which requires a three-way handshake. Our scanner specifically tests for TCP availability. UDP (User Datagram Protocol) is used for streaming and DNS, and requires different scanning techniques for detection.
Common Port Reference Table
| Port | Service | Typical Use Case |
|---|---|---|
| 22 | SSH | Secure Shell for remote server management. |
| 80 / 443 | HTTP/S | Web traffic (Standard and Secure). |
| 3306 | MySQL | Database connections (Should be firewalled). |
| 3389 | RDP | Remote Desktop Protocol for Windows servers. |